What is a negative feedback in amplifiers?
1 Answer
Negative feedback in amplifiers is a technique used to stabilize and improve the performance of electronic amplifiers. It involves feeding a portion of the output signal back to the input in such a way that it opposes any changes in the input signal. This means that if the output increases, the feedback is designed to decrease the input, and if the output decreases, the feedback is designed to increase the input. This opposing action tends to reduce the overall gain of the amplifier, hence the term "negative" feedback.
The process of negative feedback helps to achieve several benefits in amplifiers:
Improved Linearity: Negative feedback reduces distortion in the amplifier, making the output signal more faithful to the input signal.
Increased Bandwidth: It can extend the usable frequency range of the amplifier.
Enhanced Stability: Negative feedback stabilizes the amplifier against variations in component values and temperature changes.
Reduced Noise: It can lower the noise level in the amplifier circuit.
Lower Output Impedance: Negative feedback typically results in a lower output impedance, which allows the amplifier to drive loads more effectively.
Improved Distortion and Intermodulation Performance: Negative feedback can help reduce harmonic and intermodulation distortion, resulting in cleaner output signals.
The amount of negative feedback applied to an amplifier can be adjusted to achieve a balance between the above benefits and any potential drawbacks. Too much negative feedback can lead to stability issues or compromise the amplifier's overall gain and sensitivity. Therefore, amplifier designers carefully select the appropriate amount of feedback to optimize performance for the specific application.
The process of negative feedback helps to achieve several benefits in amplifiers:
Improved Linearity: Negative feedback reduces distortion in the amplifier, making the output signal more faithful to the input signal.
Increased Bandwidth: It can extend the usable frequency range of the amplifier.
Enhanced Stability: Negative feedback stabilizes the amplifier against variations in component values and temperature changes.
Reduced Noise: It can lower the noise level in the amplifier circuit.
Lower Output Impedance: Negative feedback typically results in a lower output impedance, which allows the amplifier to drive loads more effectively.
Improved Distortion and Intermodulation Performance: Negative feedback can help reduce harmonic and intermodulation distortion, resulting in cleaner output signals.
The amount of negative feedback applied to an amplifier can be adjusted to achieve a balance between the above benefits and any potential drawbacks. Too much negative feedback can lead to stability issues or compromise the amplifier's overall gain and sensitivity. Therefore, amplifier designers carefully select the appropriate amount of feedback to optimize performance for the specific application.